Television and radio networks are two examples of networks in broadcast space. A network is an organization that delivers programs that may include recorded or live content, and may include movies, radio shows, and other audio and/or video content. The content may be delivered either as linear content or nonlinear content.
Linear content is provided in a serial format in which one program follows a previous program in time. A network providing linear content can provide only one program at any given moment in time. Thus, linear content follows a schedule or a timetable that users must follow to access the linear content. The scheduling of linear content involves a process of assigning content to time slots on the network. A database of the content may contain program identifiers, titles, durations and other supporting information, and the database may be organized in a serial format based on the schedule of the linear content. Thus, based on the network and the predetermined schedule, it can be determined what linear content was accessed at any particular time.
Nonlinear content, on the other hand, is scheduled within a window of time during which users may access the nonlinear content. A network providing nonlinear content may provide one program or multiple programs, e.g. a library of content, at any given moment in time. The nonlinear content is scheduled so that it is made available for access by users during a specified window of time, such as for example, a certain number of hours, days, weeks, or months. Nonlinear content may be selected by users on-demand, and may include, for example, video on demand (VOD), Web content, and/or content provided by another delivery method that does not follow a linear schedule.
Tracking media consumption is becoming increasingly complicated, for example, with the growth of Web and mobile media usage by end users, and additional varied modes of consumption available to end users. One exemplary method of tracking media consumption is watermarking, in which content is tagged with data in a manner that is not visible or audible to end users. Watermarking processes may hide the data within content so as not to cause a degradation of the content as received by users. Such watermark data may include identification marks, time stamps and other data types. Further, the recovery of watermark data may require an understanding of how the data was originally watermarked into the content. Moreover, watermarking, once added to content, cannot be removed. Accordingly, watermarking is generally added to content at the time of transmission and/or distribution after all other processing and/or conversion has been completed.
Watermark data may include, for example, audio watermarks and/or video watermarks. Audio watermarks may include audio data that is added to an existing audio stream of content at particular time increments. The audio watermarks may be added such that they are not audible to an end user. This may be accomplished, for example, by adding the audio watermark data while music, speech, and/or other audio output is present in a program such that the audio watermark data is masked by the content's music or speech. Similarly, video watermarks may include video data that is added to an existing video stream of content at particular time increments. The video watermarks may be added such that they are not visible to an end user. This may be accomplished, for example, by adding the video watermark data to corners, edges, dark sections, and/or other portions of the video stream of a program such that the video watermark data is masked by the content's video stream.
Further, the audio and/or video watermark data may be added to the content at a particular insertion rate. The particular time increments at which watermark data is added to content may depend on the desired resolution of tracking media consumption. That is, a higher frequency of watermark data insertion would provide more frequent data points, and thus higher resolution, with respect to tracking consumption, whereas a lower frequency of watermark data insertion would provide less frequent data points, and thus lower resolution, with respect to tracking consumption.
Watermark data may be recovered from content that has been accessed by users, for example, by a process called metering. In order to recover audio and/or video watermark data, a data collection device may be present at the location in which an end user accesses the content. The data collection device may then listen to (in the case of audio watermark data) and/or view (in the case of video watermark data) the content as it is output to the end user. The data collection device may be capable of identifying and recovering the watermarks that are not audible and/or visible to end users. The recovered watermarks may be processed in the data collection device and/or may be transferred to and/or processed at other processing center(s). Then, the recovered and/or processed data may be provided to networks or other entities that request such data in order to track media consumption, for example.
For watermarking linear content, the watermark data is added at the time of transmission of the content to an end user. The watermark data that is inserted into the linear content may include an identification mark and a time stamp. The identification mark may be unique to the assigned network, such that there is a one to one relationship between the identification mark and the network. Accordingly, each network may have its own unique identification mark. Further, because linear content follows a predetermined schedule, the identification mark may be used to identify the network, and the time stamp may identify the time at which content was accessed on the network, which time stamp may then be correlated with the particular content accessed by reference to the schedule and the identified network.
For watermarking nonlinear content, the watermark data is also added at the time of transmission of the content to an end user. The watermark data that is inserted into the nonlinear content may also include an identification mark and a time stamp. The identification mark may be unique to the assigned network, such that there is a one to one relationship between the identification mark and the network. Accordingly, each network may have its own unique identification mark.
However, because nonlinear content on a network may include a library of content that does not follow a predetermined schedule but rather is made available to users within a window of time, an identification of the network and a time stamp are not sufficient to identify the particular program accessed by an end user. For example, if Network A offers five Programs A1, A2, A3, A4, A5 during a particular window of time, and end user B accesses Program A5 during this window of time, merely identifying Network A and a time stamp which falls in the window of time during which all five Programs were available is not sufficient to identify the particular Program, i.e., Program A5, that was accessed by end user B. Thus, additional data related to the particular content accessed may be added to the watermark data in order to identify the particular content accessed. However, this adds additional complexity to the watermark data that is added to content, and as more data is included in watermarks, it may become more difficult to mask such watermarking within the content such that it does not detrimentally affect the content accessed by users.
Further, because nonlinear content may be accessed by multiple users from various different devices, each copy of the same nonlinear content may be uniquely watermarked, further adding complexity and resulting in a proliferation of data that must be stored and tracked. For example, if Program A1 is offered on Network A, and end users B, C, D each access Program A1 from unique devices, such as, for example, a cell phone, a computer, and a television, then three unique copies of Program A1 are processed and converted to be delivered to each requesting end user's device, and each end user B, C, D receives a unique copy of Program A1 converted to suit his/her device. Further, each unique copy of Program A1 includes unique watermark data added at the time of transmission and/or distribution to the end user. That is, because the watermark data is added to content at the time of transmission, each copy of a program, even if it is the same program on the same network, includes unique watermark data. More specifically, although the network identification may be the same for all copies of a program offered on a particular network, each copy will include a unique identifier for the program even though the underlying program is the same for all copies sent to unique devices.
Moreover, if a program is removed from the library of nonlinear content of a network so that it is no longer available and then later reassigned to the same network again and made available for access by end users, each copy of the program accessed by an end user again includes unique watermark data. Further, if a program is reassigned from one network to another network, each copy of the program accessed by an end user on the new network again includes unique watermark data. This is the case even though the actual program being accessed is the same for all the above copies on the two different networks. Thus, the amount of watermark data that must be stored and tracked in order to track consumption of a single program may become quite large. Further, the large amount of data created by the number of unique watermarks that may identify the same network and the same accessed program may lead to errors in the tracking and analysis of data. When these complexities are multiplied by the potentially large number of programs made available on a single network, the task of storing and tracking such voluminous watermark data may become extremely complicated. The problem may be further complicated when managing several networks, each of which offers a large library of content.